On Wednesday, however, a report from TV station WHEC in Rochester, N.Y., said surgery has been pushed back to next week.

Kelly's Buffalo doctors said on March 14 that the return of the cancer was discovered when he came for follow-up tests after his initial surgery.

Dan Kelly told The Associated Press that his brother is humbled by an outpouring of prayers posted on social media. Jill Kelly has been providing updates on Twitter and her blog, where she recently posted that her husband's cancer is "aggressive" and "starting to spread."

Fellow Hall of Fame quarterback John Elway, the Denver Broncos' executive vice president, was among those who tweeted support for Kelly.

My thoughts and prayers go out to Jim Kelly and his family! There's not a stronger or tougher guy to handle this battle!!